Title

Soluble Tin(II) Macroinitiator Adducts for the Controlled Ring-Opening Polymerization of Lactones and Cyclic Carbonates

Document Type

Article

Publication Date

10-15-2002

Department

Polymers and High Performance Materials

Abstract

Polyesters and poly(ester carbonates) were synthesized via ring-opening polymerization with new tin(II) macroinitiator adducts containing oligomeric (L)-lactide (LLA,), rac-lactide (rac-LA), and is an element of-caprolactone (CL). The novel initiating species were synthesized by the reaction of LLA, rac-LA, or CL with Sn(OEt)(2) (monomer concentration/initiator concentration less than or equal to20) and then were dissolved in methylene chloride or toluene and stored in a stoppered flask for the subsequent ring-opening polymerization of cyclic esters and carbonates. The soluble tin alkoxide macroinitiators yielded predictable and quantitative initiation of polymerization for up to 1 month of storage time at room temperature. The resulting polymers displayed low polydispersity (less than or equal to 1.5), and a high monomer conversion (greater than or equal to95%) was obtained within relatively short polymerization times (less than or equal to2 h). Adjusting the monomer/macroinitiator ratio effectively controlled the molecular weights of the polymers. NMR was used to characterize the initiating species and polymer microstructure, and size exclusion chromatography was used to determine the molecular weight properties of the polymers. (C) 2002 Wiley Periodicals, Inc.

Publication Title

Journal of Polymer Science Part A: Polymer Chemistry

Volume

40

Issue

20

First Page

3434

Last Page

3442